Lucretius saw no boundary between his scientific interests and ethical claims

The reason that Lucretius spurned educated opinion and rejected a spherical Earth becomes clear when we realise that the worldview of his poem is based on source material that was written two and a half centuries earlier by Epicurus himself, the man who founded the school that Memmius was planning to build over. It is quite possible, says Lucretius, that the infinite space of the Universe contains many other worlds each with their own heavens and Earth. The entire Epicurean world-picture buttresses an ethical framework that provides a way of achieving happiness
Why did Lucretius ignore the work of contemporary astronomers such as Hipparchus and Aristarchus, who knew that the Earth is a sphere, the stars are distant and the Sun is much larger than the Earth?

Source: aeon.co